Maybe CTF is dead, but there are plenty of fun problems in the real world -- ask any scientist, engineer, or medical researcher.

There are a million places where a computer can interact with a non-digital system in a loop.

- Tune an FPGA, or a whole data-center, or just a physical computer.

- Make a drone fly somewhere.

- Design a selective toxin (or anti-toxin).

Or, you know, get more people to click on adds. All totally possible to automate.

Using real-life calculators to add? Calculate the Flag. I don't think it is dead at all. It's like mixing in board game / escape room / science / engineeer/ medical research elements.